The specific aims of this renewal application are similar to those initially proposed. The primary goals of the proposed training program in immunology are first to recruit talented and highly-motivated graduate students and postdoctoral fellows and second to provide them with first- rate training which will prepare them for careers in academic research as competitive, independent investigators. The program faculty's research interests span a wide range of immunologic questions, allowing the entering trainee a considerable breadth of choice of experimental systems, approaches, and research topics. Training is available in both animal and human systems, and there are several projects in each category that enhance our ability to attract and train M.D.'s for research careers. Another strength of the proposed training grant is the quality of the research programs of the participating faculty. This proposal includes 19 well-funded program faculty members who have productive, timely, and energetic ongoing research efforts in their diverse areas of interest. Particular areas of strength are the study of the differentiation antigens on normal and transformed myeloid cells, characterization of Fc receptors, ADCC and use of heteroconjugates, the growth and function of T lymphocytes (IL-2 and IL-2 receptor structure/function relationships, MHC restricted cytolytic T lymphocytes), the interactions of T helper cells and B cells leading to activation of B lymphocytes, the interaction of steroid hormones with the immune system, mechanisms of autoimmunity, the involvement of various immune mechanisms in resistance to infectious diseases including those caused by parasites, bacteria, and retroviruses such as HIV and mouse AIDS (MAIDS) virus, and immunotherapeutics and vaccine design. We are able at Dartmouth Medical School to attack these questions with the full range of modern immunologic, biochemical, and molecular biologic techniques. We have excellent facilities, particularly with the construction of new laboratories in 1992 at the Borwell Research Building at the new Medical Center site, are well equipped, and the Medical School has increased its support of the Immunology Program as a result of the Immunology Training Grant. The proposal also benefits from the presence of strong existing graduate programs leading to the Ph.D. degree. Training in immunology spans five departments and three graduate programs - Physiology, Pharmacology and Toxicology, and Molecular and Cellular Biology (previously known as "Biochemistry") - with the latter containing the majority of the participating faculty and students. Consistent with this organization, graduate training in immunology at Dartmouth is an interdisciplinary approach that is nurtured by a highly interactive environment in which the trainees are regularly exposed to diverse areas of faculty expertise, from clinical to basic science studies, in a variety of forums, including a number of advanced courses, weekly seminar series and journal clubs, and retreats. By these means our students and postdoctorals benefit from a vigorous faculty involvement and scientific exchange that results in maximized communication of their work, the program faculty's work, and the progress of immunology on the international level. Indeed, the key to the proposed program is the uniform intense involvement, enthusiasm, and excellence of the program faculty members.